10:28:41 <RRSAgent> RRSAgent has joined #data-shapes
10:28:46 <RRSAgent> logging to https://www.w3.org/2026/01/14-data-shapes-irc
10:28:55 <AndyS> zakim, this is SHACL Rules TF
10:28:55 <Zakim> got it, AndyS
10:29:12 <AndyS> agenda: https://www.w3.org/events/meetings/a5aa03f6-bc98-4ae6-b6e5-67d91d99bece/20260113T103000/#agenda
10:29:13 <agendabot> AndyS, sorry, I did not recognize any agenda in https://www.w3.org/events/meetings/a5aa03f6-bc98-4ae6-b6e5-67d91d99bece/20260113T103000/#agenda
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10:32:22 <AndyS> zakim, start meeting
10:32:22 <Zakim> RRSAgent, make logs Public
10:32:24 <Zakim> please title this meeting ("meeting: ..."), AndyS
10:32:36 <AndyS> meeting: SHACL Rules TF
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10:32:58 <RRSAgent> I have made the request to generate https://www.w3.org/2026/01/14-data-shapes-minutes.html AndyS
10:33:09 <DavidHabgood> present+
10:33:21 <AndyS> present+
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10:33:59 <DavidHabgood> scribe+
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10:34:02 <simonstey> present+
10:34:18 <AndyS> present+ Livio
10:34:23 <AndyS> present+ Oggy
10:34:39 <AndyS> present?
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10:35:07 <AndyS> present+ Robert
10:35:56 <DavidHabgood> Agenda: scheduling for future meetings; whether to still talk to Derta re. n3; work items for document esp. syntax variants
10:35:56 <agendabot> DavidHabgood, sorry, could not get scheduling for future meetings; whether to still talk to Derta re. n3; work items for document esp. syntax variants (code 400).
10:36:36 <DavidHabgood> Andy: agenda for today is: scheduling for future meetings; whether to still talk to Derta re. n3; work items for document esp. syntax variants
10:36:36 <AndyS> s/Derta/Doethe/
10:38:01 <DavidHabgood> timeslot: Wednesday is best for everyone, at current time 10:30 UTC
10:39:25 <DavidHabgood> AndyS: do we still want meeting with Doethe, scheduling across timezones can be difficult. Worth coming up with wording around differences, e.g. logic system w/ rules vs. datalog
10:39:56 <AndyS> https://w3c.github.io/N3/spec/
10:40:08 <AndyS> and https://w3c.github.io/N3/spec/semantics.html
10:41:30 <DavidHabgood> Andy: will try to schedule a slot on Wednesday, if not Tuesday
10:43:36 <DavidHabgood> Livio: some items still unclear, e.g. aggregates
10:44:51 <DavidHabgood> ... would be good to clarify difference w/ n3
10:45:22 <DavidHabgood> AndyS: need to be careful on difference in writing for standard vs academic paper; standard to be normative
10:46:09 <DavidHabgood> ... also have options e.g. w3c notes, or adding to github discussions as means to include other information, comparisons
10:46:38 <simonstey> q+
10:46:48 <DavidHabgood> ... suggest focus on defining SHACL rules, and see whether a comparison is required, can review comments for input
10:47:40 <simonstey> q-
10:47:59 <DavidHabgood> simonstey: will be comments on comparisons to n3, RIF; could go into primer, else expecting comments around reinventing existing
10:48:25 <DavidHabgood> Robert: is it worth justifying decisions in the spec a bit
10:48:48 <DavidHabgood> AndyS: could mention SHACL AF to show the demand for such a spec
10:49:45 <DavidHabgood> simonstey: might be better to focus on justifying decisions rather than comparisons with others
10:50:00 <DavidHabgood> Livio: can't compare against all others
10:50:13 <DavidHabgood> Robert: consider complexity of comparing with other things
10:50:57 <DavidHabgood> AndyS: the other techs show a need/demand; SHACL rules is an attempt to bring it closer to SHACL/SPARQL
10:52:02 <AndyS> s/Doethe/Dörthe/
10:52:34 <simonstey> https://www.w3.org/DesignIssues/OldNotation3Grammar.html 2001
10:52:43 <DavidHabgood> Oggy: good to understand intent/motivation for spec in addition to the specs as well
10:55:19 <DavidHabgood> Topic: syntax
10:56:05 <DavidHabgood> AndyS: RULE .. WHERE .. , IF .. THEN .., Datalog one with curly brackets. Has to be something to terminate a rule body, otherwise blurs into next rule
10:56:37 <DavidHabgood> ... EBNF strictly, rules must be on one line, char at end of line is a terminator, this is how not run into head of next production
10:57:07 <DavidHabgood> ... would need to do arbitrary lookaheads as can be many rules
10:58:44 <DavidHabgood> Livio: do we also allow backtracking, as in prolog, "goal seek" behaviour
10:59:13 <DavidHabgood> AndyS: not same as backtracking in prolog; no backtracking symbols or notion of "cut"
11:00:12 <DavidHabgood> ... can be an implementation detail. Can do brute force forward chain, query outcome
11:01:13 <DavidHabgood> ... can allow property functions as part of a SPARQL engine doing inference with rules
11:02:57 <DavidHabgood> simonstey: how would the integration work, rules and sparql
11:03:32 <DavidHabgood> AndyS: would work separately, call each other
11:04:07 <DavidHabgood> Robert: graphwise has a current rule language, has some limitations, looking to implement SHACL 1.2 incl. rules
11:04:41 <DavidHabgood> ... use cases where owl reasoning is overkill; completion of KG use cases
11:04:56 <DavidHabgood> ... negation as failure is a useful feature for these cases
11:05:53 <DavidHabgood> AndyS: would the implementation cover/be in RDF4J
11:06:29 <DavidHabgood> Robert: potentially as they're tightly related
11:07:34 <AndyS> [8]  	Rule	  ::=  	Rule1 | Rule2 | Rule3 | Declaration
11:07:34 <AndyS> [9]  	Rule1	  ::=  	'RULE' HeadTemplate 'WHERE' BodyPattern
11:07:34 <AndyS> [10]  	Rule2	  ::=  	'IF' BodyPattern 'THEN' HeadTemplate
11:07:34 <AndyS> [11]  	Rule3	  ::=  	HeadTemplate ':-' BodyPattern
11:09:49 <DavidHabgood> Andy: RULE/WHERE and IF/THEN can accommodate people's different conceptual models
11:10:05 <DavidHabgood> ... third datalog syntax :- if any could be the one to remove
11:11:08 <DavidHabgood> Livio: people will likely converge on one format; if to pick one, would pick Rule2
11:12:20 <DavidHabgood> Oggy: is there any impact with having the RDF format for rules
11:14:32 <DavidHabgood> simonstey: doesn't necessarily need to support arbitrary SHACL constructs
11:15:18 <DavidHabgood> AndyS: non single valued functions do not fit in with the current abstract syntax
11:18:13 <DavidHabgood> simonstey: Rule3 syntax it is datalog like but not quite so can be confusing anyway
11:18:43 <DavidHabgood> Robert: Rule3 similar to other syntaxes as well
11:21:05 <DavidHabgood> AndyS: actions on the end of rules, go through one pass of actions, IF THEN could be a good fit for the actions
11:22:31 <DavidHabgood> consensus is 1&2 support different mental models
11:25:09 <DavidHabgood> AndyS: actions are open, like CONSTRUCT, less restrictions, could allow more arbitrary creation of terms in an action
11:28:54 <DavidHabgood> Oggy: old problem of combining constraint language + open world language e.g. OWL; papers on compiling rules into SHACL itself
11:29:45 <AndyS> https://www.w3.org/TR/rif-owl-rl/
11:30:20 <DavidHabgood> Robert: OWL fragments, has requirements around explicit typing, could use SHACL to check syntax first, then rules on top of this
11:31:06 <DavidHabgood> Oggy: e.g. could complete type hierarchy using rules before doing other operations w/ OWL
11:32:27 <AndyS> https://www.w3.org/TR/shacl12-core/#dfn-shacl-subclass
11:33:06 <DavidHabgood> simonstey: part of historical reason for inclusion of RDFS in SHACL was to accommodate interests from different people
11:34:36 <DavidHabgood> Robert: RDFS subclassing built in can be problematic, is odd that there isn't an equivalent sub property of
11:36:04 <simonstey> eiter
11:36:18 <Oggy> Thomas Eiter
11:36:26 <simonstey> https://informatics.tuwien.ac.at/people/thomas-eiter
11:37:46 <DavidHabgood> Oggy: have a proof of completeness
11:39:06 <DavidHabgood> Livio: entailment discussion, how did it end
11:39:28 <DavidHabgood> AndyS: out of scope for rules, can refer to an entailment regime
11:43:27 <RRSAgent> I have made the request to generate https://www.w3.org/2026/01/14-data-shapes-minutes.html AndyS
11:44:34 <AndyS> s/Derta/Dörthe/
11:44:39 <RRSAgent> I have made the request to generate https://www.w3.org/2026/01/14-data-shapes-minutes.html AndyS
11:45:14 <AndyS> zakim, end meeing
11:45:14 <Zakim> I don't understand 'end meeing', AndyS
11:45:20 <AndyS> zakim, end meeting
11:45:20 <Zakim> As of this point the attendees have been DavidHabgood, AndyS, simonstey, Livio, Oggy, Robert
11:45:22 <Zakim> RRSAgent, please draft minutes
11:45:23 <RRSAgent> I have made the request to generate https://www.w3.org/2026/01/14-data-shapes-minutes.html Zakim
11:45:28 <Zakim> I am happy to have been of service, AndyS; please remember to excuse RRSAgent.  Goodbye
11:45:29 <Zakim> Zakim has left #data-shapes
11:45:40 <AndyS> rrsagent, please leave
11:45:40 <RRSAgent> I see no action items